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Regularity of weak KAM solutions and Mañé’s Conjecture

Ludovic Rifford (2011/2012)

Séminaire Laurent Schwartz — EDP et applications

We provide a crash course in weak KAM theory and review recent results concerning the existence and uniqueness of weak KAM solutions and their link with the so-called Mañé conjecture.

Relativistic stability of matter (I).

Charles L. Fefferman, Rafael de la Llave (1986)

Revista Matemática Iberoamericana

In this article, we study the quantum mechanics of N electrons and M nuclei interacting by Coulomb forces. Motivated by an important idea of Chandrasekhar and following Herbst [H], we modify the usual kinetic energy -∆ to take into account an effect from special relativity. As a result, the system can implode for unfavorable values of the nuclear charge Z and the fine structure constant α. This is analogous to the gravitational collapse of a heavy star. Our goal here is to find those values of α...

Remarks on the Lichnerowicz-Poisson cohomology

Izu Vaisman (1990)

Annales de l'institut Fourier

The paper begins with some general remarks which include the Mayer-Vietoris exact sequence, a covariant version of the Lichnerowicz-Poisson cohomology, and the definition of an associated Serre-Hochshild spectral sequence. Then we consider the regular case, and we discuss the Poisson cohomology by using a natural bigrading of the Lichnerowicz cochain complex. Furthermore, if the symplectic foliation of the Poisson manifold is either transversally Riemannian or transversally symplectic, the spectral...

Résurgence paramétrique et exponentielle petitesse de l'écart des séparatrices du pendule rapidement forcé

David Sauzin (1995)

Annales de l'institut Fourier

Henri Poincaré avait déjà remarqué que les variétés stable et instable du pendule perturbé, défini par l’hamiltonien H ( q , p , t ) = p 2 / 2 + ( - 1 + cos q ) ( 1 - μ sin ( t / ϵ ) ) , ne coïncident pas lorsque que le paramètre μ n’est pas nul, mais qu’on peut leur associer un même développement formel divergent en puissance de ϵ . Cette divergence est ici analysée au moyen de la récente théorie de la résurgence, et du calcul étranger qui permet de trouver un équivalent asymptotique de l’écart des deux variétés pour ϵ tendant vers zéro - du moins cela est-il montré...

Retracts, fixed point index and differential equations.

Rafael Ortega (2008)

RACSAM

Some problems in differential equations evolve towards Topology from an analytical origin. Two such problems will be discussed: the existence of solutions asymptotic to the equilibrium and the stability of closed orbits of Hamiltonian systems. The theory of retracts and the fixed point index have become useful tools in the study of these questions.

Robust transitivity in hamiltonian dynamics

Meysam Nassiri, Enrique R. Pujals (2012)

Annales scientifiques de l'École Normale Supérieure

A goal of this work is to study the dynamics in the complement of KAM tori with focus on non-local robust transitivity. We introduce C r open sets ( r = 1 , 2 , ⋯ , ∞ ) of symplectic diffeomorphisms and Hamiltonian systems, exhibitinglargerobustly transitive sets. We show that the C ∞ closure of such open sets contains a variety of systems, including so-calleda priori unstable integrable systems. In addition, the existence of ergodic measures with large support is obtained for all those systems. A main ingredient of...

Scattered homoclinics to a class of time-recurrent Hamiltonian systems

Gregory S. Spradlin (2007)

ESAIM: Control, Optimisation and Calculus of Variations

A second-order Hamiltonian system with time recurrence is studied. The recurrence condition is weaker than almost periodicity. The existence is proven of an infinite family of solutions homoclinic to zero whose support is spread out over the real line.

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